Systems and methods for atomic film data storage

ABSTRACT

The present disclosure provides systems and methods associated with data storage using atomic films, such as graphene, boron nitride, or silicene. A platter assembly may include at least one platter that has one or more substantially planar surfaces. One or more layers of a monolayer atomic film, such as graphene, may be positioned on a planar surface. Data may be stored on the atomic film using one or more vacancies, dopants, defects, and/or functionalized groups (presence or lack thereof) to represent one of a plurality of states in a multi-state data representation model, such as a binary, a ternary, or another base N data storage model. A read module may detect the vacancies, dopants, and/or functionalized groups (or a topographical feature resulting therefrom) to read the data stored on the atomic film.

If an Application Data Sheet (ADS) has been filed on the filing date ofthis application, it is incorporated by reference herein. Anyapplications claimed on the ADS for priority under 35 U.S.C. §§119, 120,121, or 365(c), and any and all parent, grandparent, great-grandparent,etc. applications of such applications, are also incorporated byreference, including any priority claims made in those applications andany material incorporated by reference, to the extent such subjectmatter is not inconsistent herewith.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of the earliest availableeffective filing date(s) from the following listed application(s) (the“Priority Applications”), if any, listed below (e.g., claims earliestavailable priority dates for other than provisional patent applicationsor claims benefits under 35 U.S.C. §119(e) for provisional patentapplications, for any and all parent, grandparent, great-grandparent,etc. applications of the Priority Application(s)). In addition, thepresent application is related to the “Related Applications,” if any,listed below.

PRIORITY APPLICATIONS

NONE

RELATED APPLICATIONS

U.S. patent application Ser. No. 14/013,836, titled “Systems and Methodsfor Atomic Film Data Storage,” naming Hon Wah Chin, Howard Lee Davidson,Roderick A. Hyde, Jordin T. Kare, Nicholas F. Pasch, Robert C. Petroski,David B. Tuckerman, Lowell L. Wood, Jr. as inventors, filed 29 Aug.2013, is related to the present application.

U.S. patent application Ser. No. 14/013,845, titled “Systems and Methodsfor Atomic Film Data Storage,” naming Hon Wah Chin, Howard Lee Davidson,Roderick A. Hyde, Jordin T. Kare, Nicholas F. Pasch, Robert C. Petroski,David B. Tuckerman, Lowell L. Wood, Jr. as inventors, filed 29 Aug.2013, is related to the present application.

If the listings of applications provided above are inconsistent with thelistings provided via an ADS, it is the intent of the Applicant to claimpriority to each application that appears in the Priority Applicationssection of the ADS and to each application that appears in the PriorityApplications section of this application.

All subject matter of the Priority Applications and the RelatedApplications and of any and all parent, grandparent, great-grandparent,etc. applications of the Priority Applications and the RelatedApplications, including any priority claims, is incorporated herein byreference to the extent such subject matter is not inconsistentherewith.

TECHNICAL FIELD

This disclosure relates to atomic film data storage. More specifically,this disclosure relates to systems and methods for storing data usingone or more of vacancies, dopants, defects, or functional groups inconjunction with an atomic film to represent bits of data storage.Examples of monolayer atomic films include graphene, hexagonal boronnitride, and silicene.

SUMMARY

The present disclosure provides various systems and methods associatedwith data storage using atomic films, such as monolayer atomic filmshaving uniform lattice structures. Examples of atomic films includegraphene, hexagonal boron nitride, and silicene. As provided herein,various other atomic films having uniform lattice structures may beutilized as well. In some embodiments, a platter assembly may include atleast one platter that has one or more substantially planar surfaces.One or more layers of a monolayer atomic film may be positioned on aplanar surface and used to store data. For instance, a graphene film maybe positioned on at least a portion of a substantially planar surface ofa platter assembly.

In some embodiments, vacancies in the lattice structure of the atomicfilm may represent one or more possible states, such as for example a 0or a 1 in a binary data storage system. In some embodiments, one or moredopants may be positioned in the lattice structure to represent one ormore possible states. Similarly, a functional group on the latticestructure of the monolayer atomic film may be used to represent one ormore possible states. In some embodiments, the monolayer atomic film maybe fully functionalized and the removal of functional groups may be usedto represent one or more possible states. In some embodiments, one ormore lattice defects may be used to represent one or more possiblestates.

A read module may be configured to detect an anomaly in a latticestructure that represents (alone or in combination with other anomalies)bits of data. For example, a lattice anomaly may include one or more ofa vacancy in a lattice structure, a dopant in a lattice structure, adefect in the lattice structure, and/or the presence of a functionalizedgroup on the monolayer atomic film. As described above, one or morevacancies, dopants, defects, and/or functionalized groups (presence orlack thereof) may be used to represent one of at least two possiblestates (e.g., as bits of data storage). Thus, the monolayer atomic filmmay be used to store readable data in the at least two possible statesthat can be detected/read by a read module.

Additionally, a movement assembly may move at least one of the readmodule and the platter assembly with respect to the other. For instance,the platter assembly may be a disk that rotates with respect to a readmodule. In one embodiment, the read module and the platter assembly maybe configured to function similar to single- or multi-platter magneticdisk drives, optical media, and or tape drive storage.

An example embodiment includes a graphene film deposited on a planarsurface of a platter. One or more of vacancies, dopants, defects, and/orfunctionalized groups may be used to represent 0s and 1s for binary datastorage. The platter may then be read by a read module configured todetect the vacancies, dopants, defects, and/or functionalized groups. Invarious embodiments, a write module may be configured to write 0s and 1sby adding and/or removing vacancies, dopants, lattice defects, and/orfunctionalized groups.

In some embodiments, the write module may or may not have erase/resetcapabilities. Depending on the functionalities and granularity of thewrite module, various techniques used for solid state memory devices,such as erase blocks larger than individual sectors, may be utilized toallow relatively larger regions of the graphene layer (or othermonolayer atomic film) to be erased (i.e., remove all vacancies, removedopants, remove defects, remove functionalized groups, and/orre-functionalize the entire region). In some embodiments a block of datamay be virtually erased by removing its location from a data filelisting locations of stored data, or by adding its location to a datafile listing unused locations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a substantially planar surface of a platter with amonolayer atomic film having a hexagonal lattice structure.

FIG. 1B illustrates a close-up view of the hexagonal lattice structureof the monolayer atomic film of FIG. 1A.

FIG. 2A illustrates a graphene film including two layers of a graphene.

FIG. 2B illustrates an atomic film including two layers offset withrespect to one another.

FIGS. 3A-3E illustrate various embodiments of hexagonal monolayer atomicfilms.

FIG. 4A illustrates a read assembly configured to read data encoded onan atomic film using one or more of vacancies, dopants, and functionalgroups.

FIG. 4B illustrates an alternative embodiment of a read assembly and aplatter with an atomic film thereon.

FIG. 5 illustrates a plurality of disjointed patches of a monolayeratomic film on a planar surface of a platter.

FIG. 6A illustrates a portion of a platter with a monolayer atomic filmon the surface with dopants used to represent one or more possiblestates.

FIG. 6B illustrates a portion of a platter with a monolayer atomic filmon the surface with functional groups used to represent one or morepossible states.

FIG. 7A illustrates an atomic film with a 5-7-7-5 lattice defect used torepresent one or more possible states.

FIG. 7B illustrates another example of a lattice defect used torepresent a state in a multi-state data storage.

FIG. 7C illustrates a topographical feature (a protrusion) used torepresent one or more possible states.

FIG. 8 illustrates a 5-8-5 lattice defect used to represent one or morepossible states.

FIG. 9 illustrates a topographical feature caused by defects in thelattice structure or vacancies used to represent one or more possibledata states.

FIG. 10A illustrates vacancies in a lattice structure used to representone or more possible data states.

FIG. 10B illustrates another example of a vacancy in a lattice structureused to represent one or more possible data states.

FIG. 11 illustrates vacancies used in a portion of a lattice structureused to represent a sequence of 0s and 1s.

FIG. 12 illustrates a plurality of functional groups used to represent astate in a multi-state data storage device.

FIG. 13A illustrates a fully functionalized graphene film.

FIG. 13B illustrates an alternative embodiment of a fully functionalizedgraphene film.

DETAILED DESCRIPTION

According to the various embodiments described herein, data may bestored using a monolayer atomic film, such as graphene, hexagonal boronnitride, or silicene. Modifications to the lattice structure of themonolayer atomic film may be used to represent one or more states in amulti-state data representation system. For example, a dopant or dopedregion may be used to represent a 1 in a binary data representationsystem and an un-doped region or normal lattice point may be used torepresent a 0 in the binary data system.

A monolayer atomic film may be configured to store readable data asbinary data values with, for example, the presence of a vacancy in avacancy region representing a first state and a lack of a vacancy in thevacancy region representing a second state. In other embodiments,various characteristics (e.g., quantity, size, configuration,orientation, etc.) of vacancies, dopants, functional groups, topologicalfeatures, Stone-Walls defects, and/or other lattice anomalies may beused to represent any of N possible states in an N-based data storagesystem, where N is any integer greater than 1.

In some embodiments, a platter assembly may include one or more platterseach having one or more substantially planar surfaces. A monolayeratomic film, such as graphene, may be positioned on at least one of thesubstantially planar surfaces. Using graphene as an example, multiplelayers of graphene may be positioned on a planar surface. In someembodiments, the uppermost surface may be used to store data. In otherembodiments, each layer may be used to store data. In some embodiments,multiple layers may be separated by a spacer.

The platter may comprise carbon, silicon crystal, metal, and/or plastic.For example, the platter may comprise a plastic ribbon, a plastic disk,and/or multiple layers of graphene or hexagonal boron nitride. Theplatter may be in the form of a disk, a tape, or other recognizablestorage media, although any shape and/or size may be implemented inconjunction with the various embodiments provided herein.

In some embodiments, a portion of the monolayer atomic film may bepositioned off of the platter assembly. For instance a platter mayinclude one or more holes or may be only a framework fordepositing/positioning the monolayer atomic film. In such embodiments,the monolayer atomic film may span gaps or holes in the platter and/oroverhang edges of the platter.

The monolayer atomic film may be deposited on the planar surface as asingle continuous film. In other embodiments, the monolayer atomic filmmay be deposited as a plurality of discontinuous or continuous patchesof a monolayer atomic film. The discontinuous patches may be physicallyjoined along a grain boundary or an irregular lattice boundary.

The plurality of patches may be physically separated by a gap or overlapone another. In various embodiments, the patches may be less than asquare micron, may be between one square micron and 100 squaremillimeters, or may be greater than 100 square millimeters. The patchesmay be mapped to facilitate reading the data stored on the monolayergraphene film. For example, each of the plurality of patches may bemapped based on their location on the platter assembly, their locationrelative to another patch, an orientation, and/or a thickness.

In some embodiments, a vacancy region in the lattice structure of theatomic film may represent one or more possible states, such as forexample a 0 or a 1 in a binary data storage system. In some embodiments,one or more dopants may be positioned in the lattice structure torepresent one or more possible states. Similarly, a functional group onthe lattice structure of the monolayer atomic film may be used torepresent one or more possible states. In some embodiments, themonolayer atomic film may be fully functionalized and the removal of oneor more functional groups may be used to represent one or more possiblestates.

In some embodiments, one or more lattice defects may be used torepresent one or more possible states. Examples of lattice defects in ahexagonal lattice structure of graphene include a carbon ring with morethan six carbon atoms, a carbon ring with fewer than six carbon atoms, a5-7-7-5 cluster of carbon atoms, and a 5-8-5 cluster of carbon atoms.

A description of these and other defects in graphene and other twodimensional materials is presented in Humberto Terrones et al., The roleof defects and doping in 2D graphene sheets and 1D nanoribbons, Reportson Progress in Physics 062501 (2012), which is hereby incorporated byreference in its entirety, and Florian Banhart et al., StructuralDefects in Graphene, ACS Nano 5, 26 (2011), which is also herebyincorporated by reference in its entirety.

A read module may be configured to detect one or more of a vacancyregion in a lattice structure, a dopant in a lattice structure, atopological feature, a defect, and/or the presence of a functionalizedgroup on the monolayer atomic film. As described above, one or morevacancies, dopants, topological features, defects, and/or functionalizedgroups (presence or lack thereof) may be used to represent one of atleast two possible states allowing the monolayer atomic film to storereadable data in the at least two possible states.

Thus, by detecting a vacancy, a dopant, a topological feature, a defect,or a functionalized group, the read module may read the readable data onthe planar surface of the platter by detecting the at least two states.A movement assembly may be configured to rotate at least one of the readmodule and the platter assembly with respect to the other. In otherembodiments, the platter assembly may be a tape configured to moverelative to the read module.

The read module may also include an actuator assembly configured topivot the read module within a parallel plane substantially planar to atleast a portion of the planar surface of the platter. The graphene filmmay comprise an array of readable regions (e.g., vacancy regions) eachof which defines 2 or more possible states. The regions may be arrangedin a pre-defined geometrical array (e.g., a grid pattern) or may beirregularly located (e.g., with locations stored in a data file). Eachregion may contain (or not contain) a single defect, vacancy, dopant,topographical feature, or functional group. Alternatively, each regionmay contain multiple defects, vacancies, dopants, topological features,or functional groups, characterized by their number and locations(relative to each other or to the edges or center of the region), aswell as their type.

In various embodiments, a write module may be configured to write atleast one of the states in an N state data storage system. For example,a write module may be configured to add and/or remove dopants,vacancies, topological features, lattice defects, and/or functionalgroups. A movement assembly may be adapted to move the write module andthe platter assembly relative to one another. The write module cancreate defects and associated topological features by local irradiation(ion, electron, plasmon) to remove carbon or pre-existing dopants fromthe lattice. Dopants can be added directly via a bombarding ion orindirectly via interaction of a dopant source with a (pre-existing ornewly created) vacancy or locally heated region.

Electron-based defect creation is described in Alex W. Robertson et al.,Spatial control of defect creation in graphene at the nanoscale, NatureComm. 3:1144 (2012), which is hereby incorporated by reference in itsentirety. Ion-based defect creation is described in Jian-Hao Chen etal., Defect scattering in graphene, Physical Rev. Letters 236805 (2009),which is hereby incorporated by reference in its entirety. Laser defectcreation (which can be further confined via its plasmonic analog) isdescribed in Thilanka Galwaduge et al., Laser Induced StructuralModification of Single Layer and Bilayer Graphene, American PhysicalSociety March Meeting 2010, abstract #P22.00008 (Mar. 17, 2010),available athttp://www.physics.drexel.edu/˜lowtemp/graphene_laser_induced_defects.pdf,which is hereby incorporated by reference in its entirety.

Functional groups can be added or removed by, for example, techniquesdescribed in Vasilios Georgakilas et al., Functionalization of Graphene:Covalent and Non-Covalent Approaches, Derivatives and Applications,Chemical Reviews 112, 6156 (2012); and Tapas Kuila et al., ChemicalFunctionalization of Graphene and its Applications, Progress inMaterials Science 57, 1061-1105 (2012), each of which is herebyincorporated by reference in its entirety. Sequential approaches mayalso be useful, such as defect creation by rapid removal of functionalgroups as described in Rahul Mukherjee et al., Photothermally ReducedGraphene as High-Power Anodes for Lithium-Ion Batteries, ACS Nano 6,7867 (2012), hereby incorporated by reference in its entirety.

In some embodiments, the write module may or may not have erase/resetcapabilities. Depending on the functionalities and granularity of thewrite module, various techniques used for solid state memory devices,such as erase blocks larger than individual sectors, may be utilized toallow relatively larger regions of the graphene film to be erased (i.e.,remove all vacancies, remove dopants, remove functionalized groups,and/or re-functionalize the entire region). In some embodiments a blockof data may be virtually erased by removing its location from a datafile listing locations of stored data, or by adding its location to adata file listing unused locations.

In some embodiments, the monolayer atomic film may conform substantiallyto the topography of the underlying substantially planar surface of theplatter. Accordingly, topographical features representing states fordata storage may be defined with respect to the conformal topography ofthe graphene film on the substantially planar surface of the platter. Asdescribed above, topographical features, such as hills and valleys, maybe used to store readable data.

For instance, a hill or a valley may be used to represent 1s and 0s.Alternatively, in a multi-state data representation system, a valley mayrepresent a 0, the lack of a topographical feature may represent a 1,and a hill may represent a 2. In some embodiments, the width, depth,height, length, orientation, shape, and/or other characteristics of thetopographical features may be used to represent any number of states ina multi-state data representation system.

Using topographical features to represent states, the monolayer atomicfilm may include any number of layers of, for example, graphene,hexagonal boron nitride, and/or silicene. Other atomic films havingdefined lattice structures may be utilized as well. For example, atomicfilms having rectangular, pentagonal, hexagonal, heptagonal, octagonal,etc. shape may be utilized and/or adapted for use with one or more ofthe presently described embodiments. For example, atomic films may usefew-layer thick crystals such as molybdenum disulphide, tungstendiselenide, or other metal dichalcogenides rather than monolayers suchas graphene, hexagonal boron nitride, or silicine.

In some embodiments, the monolayer atomic film may comprise graphene andthe readable data may be stored using N possible states withtopographical features representing each of the N possible states basedon size, shape, or orientation. In some embodiments the topographicalfeature may comprise an absence or addition of one or more carbon atomsfrom a nominal hexagonal lattice position, one or more adjacentnon-hexagonal carbon rings, one or more dopants in the lattice structureof the graphene, a functional group, and/or a lattice defect, such asone or more Stone-Walls defects.

For example, the topographical feature may be defined by a single dopantin the graphene film or a doped region of the graphene film. Similarly,a single vacancy, lattice defect, and/or functional group in the latticestructure may represent a state or a region of multiple vacancies,lattice defects, and/or functional groups. In some embodiments thegraphene film may be functionalized graphene. In such embodiments, theremoval or replacement of a functional group from the functionalizedgraphene may be used to represent a state in an N state datarepresentation system.

As provided above, data may be stored in an N state data representationsystem using dopants, topological features, functional groups, defects,vacancies, and/or other differentiable characteristics. In someembodiments, a state may be represented using a single dopant, singletopological feature, single functional group, single defect, singlevacancy, and/or single other differentiable characteristic. In otherembodiments, a state may be represented using a doped region, region offunctional groups, region of defects, region of topological features,region of multiple vacancies, and/or region of other differentiablecharacteristics. In some embodiments, a read module may directly detecta single (or region of) dopant, functional group, defect, vacancy,and/or other differentiable characteristic to read the readable data. Inother embodiments, a read module may read a topographical anomaly, suchas a hill/protrusion or valley/depression, caused by a single (or regionof) dopant, functional group, defect, vacancy, and/or otherdifferentiable.

Functional groups may comprise organic compounds, nanoparticles, and/orlinker molecules. A state, for example, may be defined by a plurality ofproximate functional groups, a type of the functional groups, a spatialpattern of functional groups, the replacement of a functional group withanother type of functional group, and/or a predefined mixture ofdifferent functional groups. In some embodiments, a tracking module maytrack the movement of a functional group or vacancy from a firstphysical location in the lattice structure to a second physical locationin the lattice structure.

Throughout this disclosure the terms “in” and “on” are usedinterchangeably in many instances. Thus, unless infeasible ornonsensical, the terms “in” and “on” should each be understood as “inand/or on.” For example, “a defect in a lattice structure” may includeboth a “dopant in a lattice structure” and a “dopant on a latticestructure.”

Many existing computing devices and infrastructures may be used incombination with the presently described atomic film data storageconcepts described herein. Some of the infrastructure that can be usedwith embodiments disclosed herein is already available, such asgeneral-purpose computers, computer programming tools and techniques,digital storage media, and communication links. A computing device mayinclude a processor such as a microprocessor, a microcontroller, logiccircuitry, or the like. A processor may include a special purposeprocessing device such as application-specific integrated circuits(ASIC), programmable array logic (PAL), programmable logic array (PLA),programmable logic device (PLD), field programmable gate array (FPGA),or other customizable and/or programmable device. The computing devicemay also include a machine-readable storage device such as non-volatilememory, static RAM, dynamic RAM, ROM, CD-ROM, disk, tape, magnetic,optical, flash memory, or other machine-readable storage medium. Variousaspects of certain embodiments may be implemented using hardware,software, firmware, or a combination thereof.

The embodiments of the disclosure will be best understood by referenceto the drawings, wherein like parts are designated by like numeralsthroughout. The components of the disclosed embodiments, as generallydescribed and illustrated in the figures herein, could be arranged anddesigned in a wide variety of different configurations. Furthermore, thefeatures, structures, and operations associated with one embodiment maybe applicable to or combined with the features, structures, oroperations described in conjunction with another embodiment. In otherinstances, well-known structures, materials, or operations are not shownor described in detail to avoid obscuring aspects of this disclosure.

Thus, the following detailed description of the embodiments of thesystems and methods of the disclosure is not intended to limit the scopeof the disclosure, as claimed, but is merely representative of possibleembodiments. In addition, the steps of a method do not necessarily needto be executed in any specific order, or even sequentially, nor do thesteps need to be executed only once.

FIG. 1A illustrates a substantially planar surface of a platter 100 witha monolayer atomic film having a hexagonal lattice structure. Theplatter 100 may comprise carbon, silicon crystal, metal, and/or plastic.As illustrated, the platter 100 may be shaped like a disk and may, ormay not, have a hole 105 in the center. According to variousembodiments, the platter 100 may have multiple layers of monolayeratomic films. In the illustrated embodiment, the monolayer atomic filmhas a hexagonal lattice structure. In alternative embodiments, themonolayer atomic film may have any n-polygonal lattice structure and mayinclude any number of layers. In some embodiments, each layer may beused to store data. Multiple layers may be separated by spacers. In someembodiments, the underside of the platter 100 may also have a monolayeratomic film configured to store data as well.

FIG. 1B illustrates a close-up view 110 of the hexagonal latticestructure of the monolayer atomic film on the platter 100 of FIG. 1A. Asan example, graphene may be positioned (e.g., deposited, placed, oradhered) on the platter 100. The graphene may form hexagonal bondsbetween the various carbon atoms. As described above, anomalies in thelattice structure may be used to represent one or more states in an Nstate data representation model.

FIG. 2A illustrates a graphene film 200 including two layers of agraphene 210 and 220. As illustrated, each layer of graphene 210 and 220may be in the form of a hexagonal lattice structure. Each node in theillustration may represent a carbon atom and each solid line mayrepresent a bond. In the illustrated embodiment, the dashed linesillustrate the alignment of the first layer 210 with respect to thesecond layer 220. Data may be stored in the bottom layer 220 and/or thetop layer 210.

FIG. 2B illustrates an atomic film 200 including two layers 210 and 220that are offset with respect to one another. As illustrated the bottomlayer 220 may include different types of atoms and/or molecules 240 and230 that form the hexagonal lattice structure. The top layer 210 may begraphene, hexagonal boron nitride, silicene, or some other atomic film.The top layer 210 be bonded, adhered, and/or otherwise permanently orsemi-permanently positioned on the bottom layer 220. Any of a widevariety of bonding may be utilized. For example, bonding may include Vander Wall bonds, covalent bonds, ionic bonds, and/or the like. Data maybe stored in the bottom layer 220 and/or the top layer 210.

FIGS. 3A-3E illustrate various embodiments 310, 320, 330, 340, and 350of hexagonal monolayer atomic films. In the illustrated embodiments,each of the nodes of a particular shading illustrates a unique type ofatom or molecule. For example, nodes shaded black may represent carbonatoms, nodes shaded dark grey may represent nitrogen, and nodes shadedlight grey may represent boron. Accordingly, FIGS. 3A-3E show thatvarious configurations and varieties of lattice structures are possiblein conjunction with the various embodiments described herein. Theillustrated embodiments show hexagonal lattice structures. However, thesystems and methods of using anomalies in lattice structures torepresent data, as described herein, may be adapted for use on anylattice structure having a normal N-polygonal configuration, where N isan integer greater than 2.

FIG. 4A illustrates a read assembly 400 configured to read data encodedon an atomic film 410 on a platter 420. The read assembly may include aread head 457, an arm 455, and an actuator 450. The actuator 450 may beconfigured to pivot the arm 455 and the read head 457 with respect tothe platter 420. The platter 420 may be configured to rotate. Therotation of the platter 420 in conjunction with the pivoting actuator450 may allow all areas of the atomic film 410 to be accessed by theread head 457. The read head 457 may be configured to detect anomaliesin the lattice structure of the atomic film 410. For example, the readhead 457 may be configured to detect vacancies, dopants, functionalgroups, lattice defects, the lack of functional groups, and/or otheranomalies.

In some embodiments, the read head 457 may be configured to detecttopographical features, such as hills or valleys, that may be caused byanomalies in the lattice structure. In one embodiment, the read assembly400 may comprise elements of an atomic force microscope, such as theactuator 450, the arm 455, or the read head 457. In some embodiments,the read head 457 may detect defects in the lattice structure viaphysical contact, or via changes in the atomic film's electronic,plasmonic, optical, or vibrational properties.

Electronic signatures of various graphene defects are described in I.Deretzis, Electronic transport signatures of common defects inirradiated graphene-based systems, Nuclear Instruments & Methods inPhysics Res. B 282, 108 (2012), hereby incorporated by reference in itsentirety. Electronic and vibrational signatures of Stone-Wales defectsare described in Sharmila N. Shirodkar & Umesh V. Waghmare, Electronicand vibrational signatures of Stone-Wales defects in graphene:First-principles analysis, Physical Rev. B 165401 (2012), herebyincorporated by reference in its entirety. High resolution Ramandetection of defects is described in Johannes Stadler et al., NanoscaleChemical Imaging of Single-Layer Graphene, ACS Nano 5, 8442 (2011),hereby incorporated by reference.

Small-tip electron microscopy methods such as annular dark-field imagingmay be used to provide single-atom level detection and characterizationof graphene defects, such as the methods described in Wu Zhou et al.,Probing graphene defect structures and optical properties at the singleatom level, 15th European Microscopy Congress (Sep. 17, 2012), availableathttp://www.emc2012.org.uk//documents/Abstracts/Abstracts/EMC2012_(—)0370.pdf,hereby incorporated by reference in its entirety.

Topological defects can be detected and characterized either directlyvia their topological height differences from the underlying monolayeror indirectly via their effect on electronic properties, as described inAlberto Cortijo & Maria A. H. Vozmediano, Effects of topological defectsand local curvature on the electronic properties of planar graphene,Nuclear Physics B 763, 293 (2007), hereby incorporated by reference inits entirety, and in Jannik C. Meyer et al., Direct Imaging of LatticeAtoms and Topological Defects in Graphene Membranes, Nano Letters 8,3582 (2008), hereby incorporated by reference in its entirety. Thedetection and characterization of functional groups can be performeddirectly via chemical probes, near-field spectroscopy or the like, orindirectly via their effect on the electronic or optical properties ofthe graphene.

FIG. 4B illustrates an alternative embodiment of a read assembly 475 anda platter 420 with an atomic film 410 thereon. As illustrated andpreviously described, the atomic film 410 may be a monolayer atomic filmwith a hexagonal lattice structure, such as graphene or boron nitride.Data may be stored as anomalies in the lattice structure that representone or more states in an N state data representation system. Forexample, different types of anomalies and/or the lack of an anomaly mayrepresent a state in a binary or ternary data representation system.

The read module 475 may include a read head 485 that slides along rails487 between a center post 483 and an outside post 480. The platter 420may rotate about the axis defined by the center post 483 to allow theread head 485 to access each portion of the atomic film 410. The platter420 and/or the read assembly 475 may be configured to rotate withrespect to the other. The read head 485 may be configured to detectanomalies in the lattice structure of the atomic film 410.

As above, the read head 485 may be configured to detect topographicalfeatures, such as hills or valleys, that may be caused by anomalies inthe lattice structure and/or directly detect anomalies in the latticestructure. The format, shape, size, etc. of the platter may be differentthan illustrated. For example, the platter may be in the form of a tapeconfigured to flexibly wind and unwind past a read head.

FIG. 5 illustrates a plurality of disjointed patches 515, 517, 518, and519 of a monolayer atomic film 510 on a planar surface of a platter 520of a data storage medium 500. The monolayer atomic film 510 may bedeposited on one or more of the planar surfaces of the platter 520 as asingle continuous film. In other embodiments, the monolayer atomic film510 may be deposited as a plurality of discontinuous or continuouspatches 515, 517, 518, and 519 of an atomic film. The discontinuouspatches 515, 517, 518, and 519 may be physically joined along a grainboundary or an irregular lattice boundary.

The plurality of patches 515, 517, 518, and 519 may be physicallyseparated by a gap (as illustrated) or overlap one another. In variousembodiments, the patches 515, 517, 518, and 519 may be between onesquare micron and 100 square millimeters. The patches 515, 517, 518, and519 may be mapped to facilitate reading the data stored on, for example,a graphene film 510. For instance, each of the plurality of patches 515,517, 518, and 519 may be mapped based on their location on the platter520, their location relative to another patch, an orientation on theplatter 520, and/or a thickness of a film 510.

FIG. 6A illustrates a portion of a platter with a monolayer atomic film610 on the surface with dopants 621 used to represent one or morepossible states in a multi-state data representation model. The datastorage medium 600 may be any size or shape, such as the illustrateddisk or a tape format. In some embodiments, each dopant 620 mayrepresent one of two states in a binary data representation model. Inanother embodiment, each dopant 621 may represent one of three states ina ternary data representation model. In still other embodiments, eachdopant 621 may represent one of N states in an N state datarepresentation model.

As described herein, a read module may be configured to directly detectdopants 621 and a lack of dopants 621 as, for example, 0s and 1s, in abinary data representation model. In other embodiments, a read modulemay be configured to detect topographical features caused by the dopantsas a first state (e.g., a 1 or a 0) and the lack of a topographicalfeature as a second state (e.g., a 1 or a 0). In other embodiments, aread module may be configured to detect a first type of topographicalfeature caused by one or more dopants as a first state and a second typeof topographical feature as a second state.

FIG. 6B illustrates a portion of a platter 620 with a monolayer atomicfilm 610 on the surface with functional groups 625 used to represent oneor more possible states. Similar to the embodiments described above inconjunction with FIG. 6A, functional groups 625 may be used to representone or more possible states in an N state data representation module. Asdescribed herein, a read module may be configured to directly detectfunctional groups 625 and a lack of functional groups 625 as, forexample, 0s and 1s, in a binary data representation model. In otherembodiments, a read module may be configured to detect topographicalfeatures caused by the functional groups as a first state (e.g., a 1 ora 0) and the lack of a topographical feature as a second state (e.g., a1 or a 0). In other embodiments, a read module may be configured todetect a first type of topographical feature caused by one or morefunctional groups as a first state and a second type of topographicalfeature caused by one or more functional groups as a second state.

FIG. 7A illustrates an atomic film 700 with a 5-7-7-5 lattice defectused to represent one or more possible states. As described herein, datamay be stored using an N state data representation model in which one ormore states are represented using lattice defects, such as 5-7-7-5lattice defects. In various embodiments, a read module may be configuredto directly detect a lattice defect. In other embodiments, a read modulemay be configured to detect topographical features caused by the latticedefects, such as hills/protrusions and/or valleys/depressions. In someembodiments, various types of lattice defects, such as 5-7-7-5 latticedefects and 5-8-5 lattice defects, may be used to represent states in aternary or higher level data representation model.

FIG. 7B illustrates another example of a lattice defect in an atomicfilm 710 that may be used to represent one or more states in amulti-state data storage model. As described above, any of a widevariety of lattice defects, in hexagonal lattice structures or otherN-polygonal lattice structures, may be used to directly represent one ormore states in a base N (e.g., binary, ternary, etc.) datarepresentation model. In some embodiments, any of a wide variety oflattice defects, including the illustrated lattice defect, may be usedto create distinguishable topographical features for storing data.

FIG. 7C illustrates a topographical feature (a protrusion) 750 used torepresent one or more possible states in a monolayer atomic film 710,such as graphene or hexagonal boron nitride. In the illustratedembodiment, a lattice defect 715, such as a 5-7-7-5 lattice defect, maycause the topographical feature 750.

FIG. 8 illustrates another example of a lattice defect in a monolayeratomic film 800. Specifically, FIG. 8 illustrates a 5-8-5 lattice defectin a monolayer atomic film 800. As described above, any of a widevariety of lattice defects, in hexagonal lattice structures or otherN-polygonal lattice structures, may be used to directly represent one ormore states in a base N (e.g., binary, ternary, etc.) datarepresentation model. In some embodiments, any of a wide variety oflattice defects, including the illustrated lattice defect, may be usedto create distinguishable topographical features for storing data.

FIG. 9 illustrates a region of a graphene lattice 900 with atopographical depression caused by one or more vacancies in the latticestructure and/or dopants in the lattice structure. As described herein,one or more topographical features may be used to represent one or morestates in a binary, ternary, or base N data representation model on anormally uniform lattice structure.

In some embodiments, the atomic film may be positioned on a platter. Theatomic film may conform substantially to the topography of theunderlying substantially planar surface of the platter. Accordingly,topographical features representing states for data storage may bedefined with respect to the conformal topography of the graphene film onthe substantially planar surface of the platter. Accordingly, theconformal topography of the graphene film on the platter (i.e., withoutdata) may be mapped to enable a detection of topographical featuredefined with respect to the conformal topography of the graphene film onthe platter. As described above, topographical features, such as hillsand valleys, may be used to store readable data.

FIG. 10A illustrates vacancies 1010 and 1011 in a lattice structure 1000that may be used to represent one or more possible data states. Asdescribed above, vacancies and/or lattice defects may be used todirectly or indirectly (via topographical features) represent one ormore states in a base N (e.g., binary, ternary, etc.) datarepresentation model.

FIG. 10B illustrates another example of a vacancy 1020 in a latticestructure 1050 that may be used alone or in conjunction with othervacancies to represent one or more possible states in a datarepresentation model. In some embodiments, multiple vacancies (orfunctional groups, dopants, etc.) may be used to represent a single bitor singular data unit in a data representation model.

FIG. 11 illustrates a plurality of vacancies 1110, 1120, 1130, 1140, and1150 in a region of a graphene lattice structure 1100 that may be usedto individually represent bits in an N base data representation model orcollectively represent bits in an N base data representation model. Forexample, each vacancy 1110, 1120, 1130, 1140, and 1150 may represent abit in a binary data representation model. As another example, twovacancy regions 1130 and 1140 within a predetermined region mayrepresent a 1, while a vacancy region 1110 alone may represent a 0. Insuch an embodiment, various predetermined arrangements/configurations ofvacancies (or dopants, topographical features, functional groups, and/orlack of functional groups in a fully functional graphene lattice) may beused to represent bits in any base data representation system.

For example, a first arrangement may represent a 1 in a binary datarepresentation system and a second arrangement may represent a 0 in thebinary data representation system. As another example, in a quaternarydata representation model, a first arrangement may represent a 0, asecond configuration may represent a 1, a third configuration mayrepresent a 2, and a final arrangement may represent a 3.

FIG. 12 illustrates a plurality of functional groups 1225 on a monolayeratomic film 1210 used to represent a state in a multi-state data storagedevice 1200. As described above, a singular functional group and/or acollection of functional groups may represent a bit in a multi-statedata representation model. In some embodiments, each type of functionalgroup may be used to represent a unique state in a multi-state datarepresentation model. In some embodiments, arrangements/configurationsof functional groups of one or more types may be used to representunique states in a multi-state data representation model. For instance,unique types and/or arrangements/configurations of functional groups (orvacancies, dopants, or topographical features) may be used to represent0s and 1s in a binary data representation system.

FIG. 13A illustrates a fully functionalized graphene film 1310 on aplatter 1300. As illustrated, functional groups 1325 may fullyfunctionalized the graphene film 1310.

FIG. 13B illustrates an alternative embodiment of a fully functionalizedgraphene film 1355 on a platter 1350. Functional groups 1365 may beremoved from the fully functionalized graphene film 1355. The removedfunctional groups may be used to represent one or more possible statesin a data representation model.

This disclosure has been made with reference to various exemplaryembodiments, including the best mode. However, those skilled in the artwill recognize that changes and modifications may be made to theexemplary embodiments without departing from the scope of the presentdisclosure. While the principles of this disclosure have been shown invarious embodiments, many modifications of structure, arrangements,proportions, elements, materials, and components may be adapted for aspecific environment and/or operating requirements without departingfrom the principles and scope of this disclosure. These and otherchanges or modifications are intended to be included within the scope ofthe present disclosure.

The foregoing specification has been described with reference to variousembodiments. However, one of ordinary skill in the art will appreciatethat various modifications and changes can be made without departingfrom the scope of the present disclosure. Accordingly, this disclosureis to be regarded in an illustrative rather than a restrictive sense,and all such modifications are intended to be included within the scopethereof. Likewise, benefits, other advantages, and solutions to problemshave been described above with regard to various embodiments. However,benefits, advantages, solutions to problems, and any element(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, a required, or anessential feature or element. The scope of the present invention should,therefore, be determined by the following claims.

What is claimed is:
 1. A data storage device, comprising: a platterassembly comprising at least one platter that has at least onesubstantially planar surface; a graphene film positioned on at least aportion of a substantially planar surface of a platter of the platterassembly; a plurality of topographical features formed on the graphenefilm, wherein one or more topographical features are configured torepresent one of at least two possible states, and wherein the graphenefilm is configured to store readable data in the at least two possiblestates using the topographical features; and at least one read moduleconfigured to read the readable data on the substantially planar surfaceof the platter by detecting each of the at least two states, at leastone of which states is represented by the topographical features; and amovement assembly configured to move at least one of the at least oneread module and the platter assembly with respect to the other; whereinat least two graphene films are positioned on the portion of thesubstantially planar surface of the platter of the platter assembly,wherein a plurality of topographical features is formed on each graphenefilm, wherein one or more topographical features are configured torepresent one of at least two possible states, wherein each graphenefilm is configured to store in the at least two possible states usingthe topographical features, and wherein each of the at least twographene films is separated from other graphene films by a spacer. 2.The data storage device of claim 1, wherein at least one of the graphenefilms comprises a plurality of discontinuous patches of graphene,wherein each patch of graphene has a substantially unbroken hexagonallattice structure that is not continuous with an adjacent patch ofgraphene.
 3. The data storage device of claim 2, wherein the pluralityof discontinuous patches of graphene are physically joined withirregular lattice boundaries.
 4. The data storage device of claim 2,wherein the plurality of discontinuous patches of graphene arephysically joined along a grain boundary.
 5. The data storage device ofclaim 1, wherein at least a portion of at least one of the graphenefilms is positioned off of the platter assembly.
 6. The data storagedevice of claim 1, wherein each of the plurality of topographicalfeatures is a type of topographical feature selected from the group oftopographical features consisting of: a protrusion in the graphene film,a depression in the graphene film, a topographical feature caused by adopant, a topographical feature caused by an attached functional group,and a topographical feature caused by a lattice defect.
 7. The datastorage device of claim 1, wherein at least one of the graphene filmscomprises functionalized graphene.
 8. The data storage device of claim7, wherein at least one of the plurality of topographical features isdefined by the removal of one or more functional groups from thefunctionalized graphene.
 9. The data storage device of claim 7, whereinat least one of the plurality of topographical features is defined bythe replacement of one or more of the functional groups used tofunctionalize the graphene with a different functional group.
 10. Thedata storage device of claim 7, wherein at least one of the plurality oftopographical features comprises a relative depression in thefunctionalized graphene.
 11. A method of storing data, comprising:receiving at least two graphene films positioned on at least a portionof a substantially planar surface of a platter of a platter assembly,wherein the platter assembly comprises at least one platter that has atleast one substantially planar surface, and wherein each of the at leasttwo graphene films is separated from other graphene films by a spacer;receiving a plurality of bits of digital data; and creating a pluralityof topographical features on at least one of the at least two graphenefilms, wherein one or more topographical features represent one of atleast two possible states, and wherein at least one bit of the digitaldata is stored using the at least two possible states.
 12. A method ofreading data, comprising: receiving at least two graphene filmspositioned on at least a portion of a substantially planar surface of aplatter of a platter assembly, wherein each of the at least two graphenefilms is separated from other graphene films by a spacer; readingreadable data on the substantially planar surface of the platter bydetecting each of at least two states using at least one read module;and moving at least one of the at least one read module and the platterassembly with respect to the other, wherein the platter assemblycomprises at least one platter that has at least one substantiallyplanar surface; wherein each of the at least two graphene filmscomprises a plurality of topographical features on each graphene film,wherein one or more topographical features represents one of at leasttwo possible states, and wherein readable data is stored using the atleast two possible states.
 13. The method of claim 12, wherein at leastone of the graphene films conforms substantially to the topography ofthe underlying substantially planar surface of the platter, and furthercomprising: defining the plurality of topographical features withrespect to the conformal topography of the at least onetopography-conforming graphene film on the substantially planar surfaceof the platter.
 14. The method of claim 12, wherein the platter consistsessentially of layered graphene, and wherein each of the plurality oftopographical features is formed on an outer layer of the layeredgraphene platter.
 15. The method of claim 12, wherein forming at leastone of the plurality of topographical features comprises doping one ormore portions of the graphene film.
 16. The method of claim 12, whereinforming a topographical feature comprises forming a topographical defectin a hexagonal lattice of the graphene film.
 17. The method of claim 12,wherein at least one of the graphene films comprises functionalizedgraphene.
 18. The method of claim 17, wherein at least one of theplurality of topographical features is formed by doping one or moreportions of the functionalized graphene.
 19. The method of claim 17,wherein at least one of the plurality of topographical features isformed by at least one vacancy region in the functionalized graphene,wherein a vacancy region comprises at least one vacancy in a latticestructure of the functionalized graphene.
 20. The method of claim 17,wherein at least one of the plurality of topographical featurescomprises a topographical defect in a hexagonal lattice of thefunctionalized graphene.
 21. A data storage device, comprising: aplatter assembly comprising at least one platter that has at least onesubstantially planar surface; at least two monolayer atomic filmspositioned on at least a portion of a substantially planar surface of aplatter of the platter assembly each separated by a spacing distance;and a plurality of functional groups attached to each of the monolayeratomic films, wherein one or more functional groups are configured torepresent one of at least two possible states, and wherein each of themonolayer atomic films is configured to store readable data in the atleast two possible states using the attached functional groups; at leastone read module configured to read the readable data on thesubstantially planar surface of the platter by detecting each of the atleast two states, at least one of which states is represented by thefunctional groups; and a movement assembly configured to move at leastone of the at least one read module and the platter assembly withrespect to the other.
 22. A method of storing data, comprising:receiving at least two monolayer atomic films separated by spacers andpositioned on at least a portion of a substantially planar surface of aplatter of a platter assembly, wherein the platter assembly comprises atleast one platter that has at least one substantially planar surface;and receiving a plurality of bits of digital data; and creating aplurality of functional groups on at least one of the at least twomonolayer atomic films, wherein one or more functional groups representone of at least two possible states, and wherein at least one bit of thedigital data is stored using the at least two possible states.
 23. Adata storage method, comprising: receiving at least two monolayer atomicfilms separated by a spacer and positioned on at least a portion of asubstantially planar surface of a platter of a platter assembly; readingreadable data on the substantially planar surface of the platter bydetecting each of at least two states using a read module; and moving atleast one of the module and the platter assembly with respect to theother, wherein the platter assembly comprises at least one platter thathas at least one substantially planar surface, wherein each monolayeratomic film comprises a plurality of functional groups on each monolayeratomic film, wherein one or more functional groups represent one of atleast two possible states, and wherein readable data is stored on eachmonolayer atomic film in the at least two possible states.